Perspective-gage



.(No Model.) I v D.'G. HUNTER.

PERSPECTIVE 'G'AGE.

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Q7 arng UNITED STATES PATENT--- OFFICE.

DAVID o. HUNTER, or CHICAGO, ILLINOIS.

PERSPECTIVE-GAG E.

SPECIFICATION forming part of Letters Patent No. 486,782, dated November22, 1892.

Application filed August 9, 1892. Serial No. 442,560. (No model.) I

To all whom, it may concern:

Be it known that I, DAVID C. HUNTER, a subject of the Queen of GreatBritain, residing at Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements inPerspective-Gages; and I do declare the following to be a full, clear,and exact description of the invention, such as will-enable othersskilled in the art to which it appertains to make and use the same.

My invention has relation to an improved perspective gage or instrumentthrough the medium of which the proportional length and width of thesides or parts of an object presented to the eye may be readilyascertained.

The general object of my invention is to provide such an instrument of acheap and simple construction, having its several parts so connectedthat they may be readily adjusted, so as to enable the operator todetermine the proportional size of parts of different objects; and afurther object of the invention is to provide such an instrument of suchsize and construction that it may be compactly folded and carried in thepocket without inconvenience.

Other objects and advantages will be fully understood from the followingdescription and claims,when taken in connection with the accompanyingdrawings, in which Figure 1 is a front elevation, partly in section, ofmy improved gage. Fig. 2 is a vertical longitudinal section taken in theplane indicated by the line as x of Fig. 1. Fig. 3 is a rear elevationof the instrument folded, and Fig. 4 is a front elevation with the partsfolded.

In the said drawings similar letters designate corresponding partsthroughout the several views, referring to which A indicates the body orplate of my improved instrument, which is provided at its upper end witha short lateral branch at, and is also provided upon its face with agraduated scale I), for a purpose presently set forth.

Flexibly connected to a short branch d,extending laterally from one edgeof the plate Aat an intermediate point in the length thereof, is theshort branch e of the tubular handgrasp B, which is designed when theinstrument is not in use to be folded in front of the same, as shown inFig. at of the drawings.

When the instrument is to be used, the tubular handle 13 is swung to theextended position shown in Fig. 1, in which it is held by the pivotedhook f on the branch 6, engaging the lug g on the branch d. This tubularhand-grasp B, which is intended to afford a receptacle for theplumb-bob, (presently described,) is provided at its upper end with atight-fitting cover plug or cap it and a notch or slot 1', which latteris designed to seat the cord of the plumb-bob when not in use, andthereby prevent said cord from being damaged by being caught between theend of the handle and the cover plug or cap.

Pivotally connected to the plate A at or adjacent to the lower endthereof is a short straight arm j, which is provided at an intermediatepoint in its length with an indexmark in, which when the arm is extendedat right angles to the plate rests parallel with the longitudinal edgeof said plate and enables the operator to determine when the plate isperpendicular through the medium of the pendent plumb-bob O, which isconnected by a cord Z with the swinging arm m upon the branch a of theplate A. Thus it will be seen that perpendicularity of the plate A maybe readily determined by simply holding said plate in a verticalposition until the line Z rests motionless in vertical alignment withthe mark lo. Journaled in a suitable bracket n upon the rear side of theplate A is a shaft 10, upon which is mounted a milled manipulating-wheelq and a peripherally-grooved pulley r. The manipulatingwheel, whichextends through a slotin the pla. e A, as shown,is designed to impartmovement to a shifting-cord s, which takes around the pulley q and overpulleys t u, situated adja cent to the upper and lower ends of theplate. Suitably mounted upon a slide-rod 11, arranged longitudinallyupon the face of the plate A, is a traveling index piece or finger D,which is connected to the ends of the cord 3, and is designed to bemoved upon the face of the plate through the medium of said cord by thewheel q. Pivotally connected to the plate A adjacent to the upper endthereof is the inner section w of the straight graduated arm E, theouter section as of which is connected to the inner section by a screw yor the like, whereby it may be readily removed when not desired. Thisarm E is provided at its inner end, as illustrated in Fig. 3, with acurvilinear finger-piece F, through the medium of which it may bereadily adjusted by the index-finger of the left hand in which theoperator ordinarily holds the instrument when making a calculation.

The manner of operating the instrument for the purpose stated is asfollows: it is desired to ascertain the proportional size or area of thesides of a square box or other object, in perspective, the artist firstmakes a center line upon' his canvas or board and then holds theinstrument at a ms length between his eyes and the box to be pictured,after which he adjusts the index-finger D, through the medium of thedevices described, until he sees the box between said finger D and thelower edge of the branch at. Thusit will be perceived that the operatoris enabled to determine the proportion of the front and top of the boxin perspective and to correctly divide his center line and properlylocate the upper front edge of the box. If it is found after trial thatthe plate Ais not long enough to determine the proportionalsize of thefront and top of a given object in the perspective the straightgraduated arm E may be swung upwardly into a vertical position and theobject measured between the movable finger D and the upper end of saidarm. After the proportional elevation of the front and top of the boxhas been ascertained, as described, to get the angle or line ofvanishing points in box the arm E is adjusted to a position at rightangles to the plate A, as shown in Fig. 1, and the instrument is held atarms length between the eye and the object to be measured, as beforedescribed. The arm E is then adjusted up or down until the lower edge ofsaid arm and the contiguous longitudinal edge of the main platecorrespond with the outlines of the box. Thus it will be readilyperceived that an artist is enabled to get the true proportionaldimensions of an object in perspective and correctly picture the same.

In order that the instrument may be held in a horizontal position tomake calculations when desired,1haveprovided a graduated segment of acircle M, whereby the operator may readily determine by reason of thependent bob-cord when the plate A restsin a true horizontal plane, andmay also determine the degree of the angle of inclination of said plate.In some instances it is desirable to determine the dimensions ofaninclined objectin perspective, and to this end I have provided thepivoted, curved, and graduated arm N. By the provision of this curvedand graduated arm N the artist may readily determine the angle ofinclination of an object by inclining the plate A until one of thelongitudinal edges of said plate rests parallel with one of the Wheninclined edges of the object when the cord Z will indicate upon the armN the angle of inclination. After the angle of inclination has beendetermined the dimensions may be ascertained in substantially the samemanner as before described.

From the foregoing description it will be described the same, I do notdesire to be 0011- I fined to the construction set forth, as suchchanges or modifications in the construction and relative arrangementmay be made as fairly fall within the scope of my invention.

Having described my invention, what I claim is- 1. In a perspective-gageor mathematical instrument, the combination, with a body or plate and aplumb-bob connected to said plate by a suspendingcord, of a tubularhand-grasp connected to the plate and having a notch or slot in itsupper end and a suitable means for closing the upper end of said tubularhand-grasp, substantially as speci fied.

2. In a perspective-gage or mathematical instrument, the combination,with the body or plate having the lateral branch (1, of a handgrasphaving the lateral branch 6 flexiby con-' nected to the branch 01 of theplate, the lug on the branch d, and the pivoted hook onthe branch 6,adapted to engage the said lug, substantially as and for the purpose setforth.

3-. In a perspective-gage or mathematical instrument, the combination,with a body or plate having the branch at and a plumb-bob connected tosaid plate by a suspending-cord, of a tubular handgrasp having a notchor slot in its upper end and also having the branch 6 flexibly connectedto the branch d of the plate, a suitable means for closing the upper endof the hand-grasp, a lug on the branch d, and a pivoted hook on thebranch e, adapted to engage said lug, substantially as and for thepurpose set forth.

4. In a perspective-gage, the combination of a graduated body or plate,an index-piece adapted to be adjusted on the body or plate, and agraduated arm E, pivotally connected to said body or plate and adaptedto be swung into alignment with the same, so as to serve, in conjunctionwith the index-piece, for indicating the proportional size of the frontand top of an object in perspective, substantially as specified.

5. In a perspective-gage, the combination of a graduated body or plate,an index-piece adapted to be adjusted on said body or plate, the arm 7,connected to the plate and havingan index-mark, a plumb-bob and a cordconnecting said plumb-bob to the plate, substantially as specified.

6. In a perspective-gage or mathematical instrument, the combination ofa graduated body or plate, an index-piece adapted to be adjusted on saidbody or plate, a curvilinear graduated arm connected to the body orplate, and a plumb-bob connected by a cord to the body or plate,substantially as specified.

7.. In a perspective-gage or mathematical instrument, the combination,with a graduated body or plate, an index-piece adjustable on said bodyor plate, and a straight graduated arm connected to the body or plate,of a curvilinear graduated arm connected to the body or plate andaplumb-bob connected by a suspending-cord to the body or plate,substantially as specified.

8. A perspective gage or mathematical instrument embodying the followinginstrumentalities, viz: a graduated body or plate, an index-pieceadjustable on the body or plate, a straight graduated arm pivotallyconnected to the body or plate, a curvilinear graduated arm pivotallyconnected to the body or plate, the short arm j, also pivotallyconnected to the body or plate and having the index-mark, and aplumb-bob suspended from the body or plate, substantially as specified.

9. In a perspective-gage or mathematical instrument, the combination,with the graduated body or plate, of the index-piece, the shaft 0, themanipulating-wheel q, mounted on said shaft, the pulley 1", also mountedon the shaft 10, the pulleys tu, and the cord 8, taking around thepulley r and over the pulleys t u and having its ends connected to theindex-piece, substantially as and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

DAVID C. HUNTER.

Witnesses:

B. GIRoUX, ALF. E. SCHILLING.

